xref: /openbmc/linux/net/hsr/hsr_device.c (revision 74be2d3b)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright 2011-2014 Autronica Fire and Security AS
3  *
4  * Author(s):
5  *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
6  *
7  * This file contains device methods for creating, using and destroying
8  * virtual HSR devices.
9  */
10 
11 #include <linux/netdevice.h>
12 #include <linux/skbuff.h>
13 #include <linux/etherdevice.h>
14 #include <linux/rtnetlink.h>
15 #include <linux/pkt_sched.h>
16 #include "hsr_device.h"
17 #include "hsr_slave.h"
18 #include "hsr_framereg.h"
19 #include "hsr_main.h"
20 #include "hsr_forward.h"
21 
22 static bool is_admin_up(struct net_device *dev)
23 {
24 	return dev && (dev->flags & IFF_UP);
25 }
26 
27 static bool is_slave_up(struct net_device *dev)
28 {
29 	return dev && is_admin_up(dev) && netif_oper_up(dev);
30 }
31 
32 static void __hsr_set_operstate(struct net_device *dev, int transition)
33 {
34 	write_lock_bh(&dev_base_lock);
35 	if (dev->operstate != transition) {
36 		dev->operstate = transition;
37 		write_unlock_bh(&dev_base_lock);
38 		netdev_state_change(dev);
39 	} else {
40 		write_unlock_bh(&dev_base_lock);
41 	}
42 }
43 
44 static void hsr_set_operstate(struct hsr_port *master, bool has_carrier)
45 {
46 	if (!is_admin_up(master->dev)) {
47 		__hsr_set_operstate(master->dev, IF_OPER_DOWN);
48 		return;
49 	}
50 
51 	if (has_carrier)
52 		__hsr_set_operstate(master->dev, IF_OPER_UP);
53 	else
54 		__hsr_set_operstate(master->dev, IF_OPER_LOWERLAYERDOWN);
55 }
56 
57 static bool hsr_check_carrier(struct hsr_port *master)
58 {
59 	struct hsr_port *port;
60 
61 	ASSERT_RTNL();
62 
63 	hsr_for_each_port(master->hsr, port) {
64 		if (port->type != HSR_PT_MASTER && is_slave_up(port->dev)) {
65 			netif_carrier_on(master->dev);
66 			return true;
67 		}
68 	}
69 
70 	netif_carrier_off(master->dev);
71 
72 	return false;
73 }
74 
75 static void hsr_check_announce(struct net_device *hsr_dev,
76 			       unsigned char old_operstate)
77 {
78 	struct hsr_priv *hsr;
79 
80 	hsr = netdev_priv(hsr_dev);
81 
82 	if (hsr_dev->operstate == IF_OPER_UP && old_operstate != IF_OPER_UP) {
83 		/* Went up */
84 		hsr->announce_count = 0;
85 		mod_timer(&hsr->announce_timer,
86 			  jiffies + msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL));
87 	}
88 
89 	if (hsr_dev->operstate != IF_OPER_UP && old_operstate == IF_OPER_UP)
90 		/* Went down */
91 		del_timer(&hsr->announce_timer);
92 }
93 
94 void hsr_check_carrier_and_operstate(struct hsr_priv *hsr)
95 {
96 	struct hsr_port *master;
97 	unsigned char old_operstate;
98 	bool has_carrier;
99 
100 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
101 	/* netif_stacked_transfer_operstate() cannot be used here since
102 	 * it doesn't set IF_OPER_LOWERLAYERDOWN (?)
103 	 */
104 	old_operstate = master->dev->operstate;
105 	has_carrier = hsr_check_carrier(master);
106 	hsr_set_operstate(master, has_carrier);
107 	hsr_check_announce(master->dev, old_operstate);
108 }
109 
110 int hsr_get_max_mtu(struct hsr_priv *hsr)
111 {
112 	unsigned int mtu_max;
113 	struct hsr_port *port;
114 
115 	mtu_max = ETH_DATA_LEN;
116 	hsr_for_each_port(hsr, port)
117 		if (port->type != HSR_PT_MASTER)
118 			mtu_max = min(port->dev->mtu, mtu_max);
119 
120 	if (mtu_max < HSR_HLEN)
121 		return 0;
122 	return mtu_max - HSR_HLEN;
123 }
124 
125 static int hsr_dev_change_mtu(struct net_device *dev, int new_mtu)
126 {
127 	struct hsr_priv *hsr;
128 
129 	hsr = netdev_priv(dev);
130 
131 	if (new_mtu > hsr_get_max_mtu(hsr)) {
132 		netdev_info(dev, "A HSR master's MTU cannot be greater than the smallest MTU of its slaves minus the HSR Tag length (%d octets).\n",
133 			    HSR_HLEN);
134 		return -EINVAL;
135 	}
136 
137 	dev->mtu = new_mtu;
138 
139 	return 0;
140 }
141 
142 static int hsr_dev_open(struct net_device *dev)
143 {
144 	struct hsr_priv *hsr;
145 	struct hsr_port *port;
146 	char designation;
147 
148 	hsr = netdev_priv(dev);
149 	designation = '\0';
150 
151 	hsr_for_each_port(hsr, port) {
152 		if (port->type == HSR_PT_MASTER)
153 			continue;
154 		switch (port->type) {
155 		case HSR_PT_SLAVE_A:
156 			designation = 'A';
157 			break;
158 		case HSR_PT_SLAVE_B:
159 			designation = 'B';
160 			break;
161 		default:
162 			designation = '?';
163 		}
164 		if (!is_slave_up(port->dev))
165 			netdev_warn(dev, "Slave %c (%s) is not up; please bring it up to get a fully working HSR network\n",
166 				    designation, port->dev->name);
167 	}
168 
169 	if (designation == '\0')
170 		netdev_warn(dev, "No slave devices configured\n");
171 
172 	return 0;
173 }
174 
175 static int hsr_dev_close(struct net_device *dev)
176 {
177 	/* Nothing to do here. */
178 	return 0;
179 }
180 
181 static netdev_features_t hsr_features_recompute(struct hsr_priv *hsr,
182 						netdev_features_t features)
183 {
184 	netdev_features_t mask;
185 	struct hsr_port *port;
186 
187 	mask = features;
188 
189 	/* Mask out all features that, if supported by one device, should be
190 	 * enabled for all devices (see NETIF_F_ONE_FOR_ALL).
191 	 *
192 	 * Anything that's off in mask will not be enabled - so only things
193 	 * that were in features originally, and also is in NETIF_F_ONE_FOR_ALL,
194 	 * may become enabled.
195 	 */
196 	features &= ~NETIF_F_ONE_FOR_ALL;
197 	hsr_for_each_port(hsr, port)
198 		features = netdev_increment_features(features,
199 						     port->dev->features,
200 						     mask);
201 
202 	return features;
203 }
204 
205 static netdev_features_t hsr_fix_features(struct net_device *dev,
206 					  netdev_features_t features)
207 {
208 	struct hsr_priv *hsr = netdev_priv(dev);
209 
210 	return hsr_features_recompute(hsr, features);
211 }
212 
213 static int hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev)
214 {
215 	struct hsr_priv *hsr = netdev_priv(dev);
216 	struct hsr_port *master;
217 
218 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
219 	if (master) {
220 		skb->dev = master->dev;
221 		hsr_forward_skb(skb, master);
222 	} else {
223 		atomic_long_inc(&dev->tx_dropped);
224 		dev_kfree_skb_any(skb);
225 	}
226 	return NETDEV_TX_OK;
227 }
228 
229 static const struct header_ops hsr_header_ops = {
230 	.create	 = eth_header,
231 	.parse	 = eth_header_parse,
232 };
233 
234 static void send_hsr_supervision_frame(struct hsr_port *master,
235 				       u8 type, u8 hsr_ver)
236 {
237 	struct sk_buff *skb;
238 	int hlen, tlen;
239 	struct hsr_tag *hsr_tag;
240 	struct hsr_sup_tag *hsr_stag;
241 	struct hsr_sup_payload *hsr_sp;
242 	unsigned long irqflags;
243 
244 	hlen = LL_RESERVED_SPACE(master->dev);
245 	tlen = master->dev->needed_tailroom;
246 	skb = dev_alloc_skb(sizeof(struct hsr_tag) +
247 			    sizeof(struct hsr_sup_tag) +
248 			    sizeof(struct hsr_sup_payload) + hlen + tlen);
249 
250 	if (!skb)
251 		return;
252 
253 	skb_reserve(skb, hlen);
254 
255 	skb->dev = master->dev;
256 	skb->protocol = htons(hsr_ver ? ETH_P_HSR : ETH_P_PRP);
257 	skb->priority = TC_PRIO_CONTROL;
258 
259 	if (dev_hard_header(skb, skb->dev, (hsr_ver ? ETH_P_HSR : ETH_P_PRP),
260 			    master->hsr->sup_multicast_addr,
261 			    skb->dev->dev_addr, skb->len) <= 0)
262 		goto out;
263 	skb_reset_mac_header(skb);
264 	skb_reset_network_header(skb);
265 	skb_reset_transport_header(skb);
266 
267 	if (hsr_ver > 0) {
268 		hsr_tag = skb_put(skb, sizeof(struct hsr_tag));
269 		hsr_tag->encap_proto = htons(ETH_P_PRP);
270 		set_hsr_tag_LSDU_size(hsr_tag, HSR_V1_SUP_LSDUSIZE);
271 	}
272 
273 	hsr_stag = skb_put(skb, sizeof(struct hsr_sup_tag));
274 	set_hsr_stag_path(hsr_stag, (hsr_ver ? 0x0 : 0xf));
275 	set_hsr_stag_HSR_ver(hsr_stag, hsr_ver);
276 
277 	/* From HSRv1 on we have separate supervision sequence numbers. */
278 	spin_lock_irqsave(&master->hsr->seqnr_lock, irqflags);
279 	if (hsr_ver > 0) {
280 		hsr_stag->sequence_nr = htons(master->hsr->sup_sequence_nr);
281 		hsr_tag->sequence_nr = htons(master->hsr->sequence_nr);
282 		master->hsr->sup_sequence_nr++;
283 		master->hsr->sequence_nr++;
284 	} else {
285 		hsr_stag->sequence_nr = htons(master->hsr->sequence_nr);
286 		master->hsr->sequence_nr++;
287 	}
288 	spin_unlock_irqrestore(&master->hsr->seqnr_lock, irqflags);
289 
290 	hsr_stag->HSR_TLV_type = type;
291 	/* TODO: Why 12 in HSRv0? */
292 	hsr_stag->HSR_TLV_length =
293 				hsr_ver ? sizeof(struct hsr_sup_payload) : 12;
294 
295 	/* Payload: MacAddressA */
296 	hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload));
297 	ether_addr_copy(hsr_sp->macaddress_A, master->dev->dev_addr);
298 
299 	if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))
300 		return;
301 
302 	hsr_forward_skb(skb, master);
303 	return;
304 
305 out:
306 	WARN_ONCE(1, "HSR: Could not send supervision frame\n");
307 	kfree_skb(skb);
308 }
309 
310 /* Announce (supervision frame) timer function
311  */
312 static void hsr_announce(struct timer_list *t)
313 {
314 	struct hsr_priv *hsr;
315 	struct hsr_port *master;
316 	unsigned long interval;
317 
318 	hsr = from_timer(hsr, t, announce_timer);
319 
320 	rcu_read_lock();
321 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
322 
323 	if (hsr->announce_count < 3 && hsr->prot_version == 0) {
324 		send_hsr_supervision_frame(master, HSR_TLV_ANNOUNCE,
325 					   hsr->prot_version);
326 		hsr->announce_count++;
327 
328 		interval = msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
329 	} else {
330 		send_hsr_supervision_frame(master, HSR_TLV_LIFE_CHECK,
331 					   hsr->prot_version);
332 
333 		interval = msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
334 	}
335 
336 	if (is_admin_up(master->dev))
337 		mod_timer(&hsr->announce_timer, jiffies + interval);
338 
339 	rcu_read_unlock();
340 }
341 
342 static void hsr_del_ports(struct hsr_priv *hsr)
343 {
344 	struct hsr_port *port;
345 
346 	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
347 	if (port)
348 		hsr_del_port(port);
349 
350 	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
351 	if (port)
352 		hsr_del_port(port);
353 
354 	port = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
355 	if (port)
356 		hsr_del_port(port);
357 }
358 
359 /* This has to be called after all the readers are gone.
360  * Otherwise we would have to check the return value of
361  * hsr_port_get_hsr().
362  */
363 static void hsr_dev_destroy(struct net_device *hsr_dev)
364 {
365 	struct hsr_priv *hsr = netdev_priv(hsr_dev);
366 
367 	hsr_debugfs_term(hsr);
368 	hsr_del_ports(hsr);
369 
370 	del_timer_sync(&hsr->prune_timer);
371 	del_timer_sync(&hsr->announce_timer);
372 
373 	hsr_del_self_node(hsr);
374 	hsr_del_nodes(&hsr->node_db);
375 }
376 
377 static const struct net_device_ops hsr_device_ops = {
378 	.ndo_change_mtu = hsr_dev_change_mtu,
379 	.ndo_open = hsr_dev_open,
380 	.ndo_stop = hsr_dev_close,
381 	.ndo_start_xmit = hsr_dev_xmit,
382 	.ndo_fix_features = hsr_fix_features,
383 	.ndo_uninit = hsr_dev_destroy,
384 };
385 
386 static struct device_type hsr_type = {
387 	.name = "hsr",
388 };
389 
390 void hsr_dev_setup(struct net_device *dev)
391 {
392 	eth_hw_addr_random(dev);
393 
394 	ether_setup(dev);
395 	dev->min_mtu = 0;
396 	dev->header_ops = &hsr_header_ops;
397 	dev->netdev_ops = &hsr_device_ops;
398 	SET_NETDEV_DEVTYPE(dev, &hsr_type);
399 	dev->priv_flags |= IFF_NO_QUEUE;
400 
401 	dev->needs_free_netdev = true;
402 
403 	dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
404 			   NETIF_F_GSO_MASK | NETIF_F_HW_CSUM |
405 			   NETIF_F_HW_VLAN_CTAG_TX;
406 
407 	dev->features = dev->hw_features;
408 
409 	/* Prevent recursive tx locking */
410 	dev->features |= NETIF_F_LLTX;
411 	/* VLAN on top of HSR needs testing and probably some work on
412 	 * hsr_header_create() etc.
413 	 */
414 	dev->features |= NETIF_F_VLAN_CHALLENGED;
415 	/* Not sure about this. Taken from bridge code. netdev_features.h says
416 	 * it means "Does not change network namespaces".
417 	 */
418 	dev->features |= NETIF_F_NETNS_LOCAL;
419 }
420 
421 /* Return true if dev is a HSR master; return false otherwise.
422  */
423 inline bool is_hsr_master(struct net_device *dev)
424 {
425 	return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
426 }
427 
428 /* Default multicast address for HSR Supervision frames */
429 static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
430 	0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
431 };
432 
433 int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
434 		     unsigned char multicast_spec, u8 protocol_version,
435 		     struct netlink_ext_ack *extack)
436 {
437 	struct hsr_priv *hsr;
438 	int res;
439 
440 	hsr = netdev_priv(hsr_dev);
441 	INIT_LIST_HEAD(&hsr->ports);
442 	INIT_LIST_HEAD(&hsr->node_db);
443 	INIT_LIST_HEAD(&hsr->self_node_db);
444 	spin_lock_init(&hsr->list_lock);
445 
446 	ether_addr_copy(hsr_dev->dev_addr, slave[0]->dev_addr);
447 
448 	/* Make sure we recognize frames from ourselves in hsr_rcv() */
449 	res = hsr_create_self_node(hsr, hsr_dev->dev_addr,
450 				   slave[1]->dev_addr);
451 	if (res < 0)
452 		return res;
453 
454 	spin_lock_init(&hsr->seqnr_lock);
455 	/* Overflow soon to find bugs easier: */
456 	hsr->sequence_nr = HSR_SEQNR_START;
457 	hsr->sup_sequence_nr = HSR_SUP_SEQNR_START;
458 
459 	timer_setup(&hsr->announce_timer, hsr_announce, 0);
460 	timer_setup(&hsr->prune_timer, hsr_prune_nodes, 0);
461 
462 	ether_addr_copy(hsr->sup_multicast_addr, def_multicast_addr);
463 	hsr->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec;
464 
465 	hsr->prot_version = protocol_version;
466 
467 	/* FIXME: should I modify the value of these?
468 	 *
469 	 * - hsr_dev->flags - i.e.
470 	 *			IFF_MASTER/SLAVE?
471 	 * - hsr_dev->priv_flags - i.e.
472 	 *			IFF_EBRIDGE?
473 	 *			IFF_TX_SKB_SHARING?
474 	 *			IFF_HSR_MASTER/SLAVE?
475 	 */
476 
477 	/* Make sure the 1st call to netif_carrier_on() gets through */
478 	netif_carrier_off(hsr_dev);
479 
480 	res = hsr_add_port(hsr, hsr_dev, HSR_PT_MASTER, extack);
481 	if (res)
482 		goto err_add_master;
483 
484 	res = register_netdevice(hsr_dev);
485 	if (res)
486 		goto err_unregister;
487 
488 	res = hsr_add_port(hsr, slave[0], HSR_PT_SLAVE_A, extack);
489 	if (res)
490 		goto err_add_slaves;
491 
492 	res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B, extack);
493 	if (res)
494 		goto err_add_slaves;
495 
496 	hsr_debugfs_init(hsr, hsr_dev);
497 	mod_timer(&hsr->prune_timer, jiffies + msecs_to_jiffies(PRUNE_PERIOD));
498 
499 	return 0;
500 
501 err_add_slaves:
502 	unregister_netdevice(hsr_dev);
503 err_unregister:
504 	hsr_del_ports(hsr);
505 err_add_master:
506 	hsr_del_self_node(hsr);
507 
508 	return res;
509 }
510